Relampable cap assembly with camseated lamp holder members



M. D. FULLER Jan. 31, 1967 REL/\MPABLE CAP ASSEMBLY WITH CAM-SEATED LAMP HOLDER MEMB 2 Sheets-Sheet 1 Filed Jan. 8, 1965 I'1\VI5NTOR. MAl/E/C'E' D. FULLER ,4 r TOPA/EY M. D. FULLER Jan.3l, 1 967 RELAMPABLE CAP ASSEMBLY WITH CAM-SEATED LAMP HOLDER MEMBERS 2 Sheets-Sheet .2

Filed Jan.

lNVli/VIOR. M/we/a a P044563 A FTOAA/IE'V engageable base and head members.

3 302,195 RELAMPABLE CA1 ASSEMBLY WITH CAM- SEATED LAMP HOLDER MEMBERS Maurice ll). Fuller, Seattle, Wash, assignor to Kerry- Manufacturing Co., Seattle, Wash., a corporation of Washington Filed Jan. 8, 1965, Ser. No. 424,392 16 Claims. (Cl. 340-881) This invention relates to relampable illuminated pushbutton or like cap assemblies and more particularly concerns an improved type of lamp holder with releasably The invention is herein illustrativelydescribed by reference to the presently preferred embodiment thereof; however, it will be obvious that certain modifications and changes therein with respect to details may be made without departing from the essential features involved.

Abroad object hereof is to provide a reliable and practicable means by which to relamp a push-button or other cap assembly without necessity for use of tools nor for gaining access to the back side of the panel in or upon which the assembly is mounted. A related object is to permit such relamping without necessity for pushing inwardly on the head or cap in the process. Thus in the case of push-button switch applications relamping may be achieved without interfering with the existing setting of the switch.

A further object of this invention is to devise a connecting mechanism for the complemental socket and lamp holder members of a relampable cap assembly which is unaffected by shock and vibration and which is otherwise generally reliable in its electrical connecting and mechanical securing functions. A related object is to achieve, with this dependability, a rugged, durable, and compact simplicity in the construction and mode, of operation of the releasable connecting mechanism parts.

A broad object hereof is to provide a new and improved holder and electrical'coupling device generally useful for electrical components and the like.

In accordance with this invention as herein disclosed with reference to -a push-button cap assembly, a base member adapted to be mounted on the actuator of an electric switch is releasably engageable with a cap or head member to enclose an electric indicator lamp and form a circuit connection for the lamp. In order to connect them together, these two members are rotated relatively about a common longitudinal axis with the keying surfaces on the mutually adjacent ends of the members in sliding'contact. These keying surfaces maintain separation of the members during such rotation until a step formation is reached in the keying surfaces permitting the members to advance longitudinally into seated relationship. As an important feature, cooperable rotationactuated camming elements are carried by the respective members, the camming element on one such member being adapted for longitudinal extension and retraction movement thereon. This latter camming element is extended by the interaction of the camming elements during relative rotation of the members in one direction. A spring or other force-producing means resisting such extension of the longitudinally movable camming element applies a force to its associated member drawing the member to its seat when during the described rotation the step formation in the keying surfaces is reached. Thereupon the step formation in such surfaces prevents reverse relative rotation between the members and thus cooperates with the force-producing means and the camming elements to hold the members locked together. Disconnection of the members is readily eifectuated by manually drawing the cap member longitudinally outward sufficiently to clear the steps in the keying surf-aces 3,302,195 Patented Jan. 31, 1967 and thereupon rotating the cap member in the reverse direction to disengage the camming elements, such disengaging rotative action being aided by the force-producing means.

Because the cam elements interact to draw the cap member inwardly towards its seated position through the medium of the force-producing means the cap member need not be pushed inwardly to eifectuate interconnection of the members. Further, the requirement that the cap member be drawn longitudinally outward through a predetermined displacement against the resistance of the force-producing means before initiation of disengagement of the camming elements can be eifectuated insures reliable and undisturbed securement of the members together until relamping is necessary.

In the disclosed form of the invention certain objectives and advantages are enhanced by the construction in which the camming elements comprise slidably interfitting sleeves. The wall of one sleeve, preferably the outer, incorporates an inclined camming slot, while the other sleeve carries a cooperable follower pin engageable in the slot, the lamp or other electrical component being normally held within one sleeve and being insertable therewith into the other sleeve to make electrical contact with a terminal element therein. The keying surfaces are formed as the end edges of tubular extensions of the respective members, that on the cap member being part of an enclosure for the helical spring which surrounds the holder sleeve and interacts between stops formed on such sleeve and on the tubular member.

These and other features, objects and advantages of the invention will become more fully evident from the fol- .lowing description thereof by reference to the accompanying drawings.

FIGURE 1 is an isometric view of the cap assembly with the head and base members occupying relative positions corresponding to a beginning stage of interconnecting movement; FIGURE 2 is a view similar to FIGURE 1 with the members seated together in interconnected relationship; FIGURE 3 is a similar view with the members drawn apart longitudinally as the initial step in disconnection; and FIGURE 4 is a similar view with the members occupying relative positions corresponding to a succeeding stage in the process of disconnection.

FIGURE 5 is a side view, with parts broken away in section to show details of construction, the view corresponding to FIGURE 1 with regard to the relative positions of the parts.

FIGURES 6 and 7 are views similar to FIGURE 5 but with parts shown in the positions corresponding to FIG- URES 2 and 3 respectively.

FIGURE 8 is an exploded isometric view with the parts separated along the common axis of the device.

FIGURE 9 is an isometric view of the body element of the head member turned to the aspect of FIGURE 8.

Referring to the drawings, the illustrated cap assembly comprises a base or socket unit B and cooperable head or cap unit C releasably interconnectable therewith. Head unit. C includes a sleeve-like camming element 10 into which the globe end of an electric lamp L may be inserted with the flange L1 of the lamp seated against the inner end 10a of the sleeve 10. Oppositely directed pins 10!) mounted on the exterior of the element 10 serve as cam followers, these being located adjacent the end 10a. The sleeve-like member 10 includes an enlargement having one or more flattened sides 10c.

The sleeve-like camming element 10 is closed at its outer end by a translucent disk 14 fixedly retained in the enlarged end of the sleeve and having a projecting flange 14a which serves as a stop for one end of a helical spring 12 which slidably encircles the enlarged sleeve portion 100. The camming element 10 with its end closure disk 14 and its spring 12 then is inserted endwise into the enlarged cylindrically chambered portion 16a of the cap member body 16. Cap body 16 has a generally square flange 16b on the outer extremity thereof, and a tubular portion 160 projecting endwise oppositely from the flange 16b. A window 16 at the juncture between the tubular and chambered portions 160 and 16a is shaped in substantial conformity with the fiatsided sleeve portion 100 so as to permit free longitudinal sliding of the camming element in the cap body while preventing relative rotation therebetween. At this same juncture a shoulder or step 1611 is formed serving as a stop for the inner end of spring 12 opposite that contacting the flange 14a.

A translucent indicator panel (With or without indicia markings thereon) is then placed over the outer end face of the square flange 16b and is retained in such position by a frame 22 the flanged end of which is crimped over the rear edge of the flange 16b at suitable locations 22a. The frame 22 then serves to maintain the parts of the cap member in assembled relationship, preferably with the spring 12 under slight compression.

In the described assembled relationship of the cap member components the end portion of the camming element 10 carrying the follower pins 10b and the projecting base of the lamp L projects through and beyond the tubular portion 160 for insertion into a slightly larger socketing sleeve-like member 24 of base member B. Sleeve 24 also serves as a camming element, having inclined camming slots 24a formed in opposite wall locations extending inwardly from the end of the sleeve which receives the sleeve 10. These open-end slots direct the cam follower pins 101) so as to draw the camming element 10 more deeply into the sleeve 24 accompanying progressive relative rotation between the camming elements in one direction. At their inner ends the incline of the slots changes from an acute angle to substantially right angles to the longitudinal axis.

Within and upon the base of the sleeve-like member 24 is mounted a lamp terminal unit 24b having one or more electric contacts 24c therein engageable with similar contacts on the base of lamp L with the parts of the cap assembly seated together. The contact(s) 240 is or may be spring loaded as indicated in FIGURE 5, using suitable or conventional construction, so that the final movement of the lamp into the socketed position is accompanied by yielding of the contact 240, assuring a measured degree of contact pressure for electric circuit continuity. An electric lead conductor 24d extends from the con tact 240 to a suitable connecting point (not shown), and the socket and terminal unit 24b is usually adapted for connection to an electric switch 26 (shown by broken lines) suitably mounted as by the bracket 28 to the indicator or switch panel 30, such that the cap assembly as a unit may serve as an illuminatable pushbutton for operating the switch 26. The details of the switch and its mounting arrangement as well as its coupling to the electric terminal unit 24b are not shown since they are in no way essential to this invention or an understanding thereof.

Surrounding and mounted fixedly upon the camming sleeve element 24 is an annular enclosure 32 having a projecting tubular portion 32a and an annular ring portion 32b intermediate the ends of the enclosure. The length of the tubular portion 32a projecting beyond the adjacent end face of the ring portion 32b is substantially equal to the length of the tubular portion 160 projecting beyond the exterior shoulder 16g formed at the juncture between the camming sleeve element 10 and the enlarged chambered portion 16 of the cap body.

The two tubular portions 32a and 160 have a similar configuration and serve as keying elements operative in the process of interconnecting the members and in main taining them interconnected. The tubular portion 160 includes circumferentially extending edge portions 16d and 16e longitudinally offset from each other by a step formation 16 Typically these edge portions 16d and 16e lie in planes perpendicular to the longitudinal axis of the cap body 16 and each subtends an arc in the vicinity of or more. At the ends of the edge portions 16d and 16s opposite the step 16 the wall length of the tubular member 16c drops abruptly to the level of the shoulder surface 16g to form second and third steps. The tubular portion 32a is of similar form, including the circumferentially extending edge portion 32d corresponding to the edge portion 16d, and the circumferential extending edge portion 32c corresponding to 16a and interconnected with the edge portion 32d by a longitudinally extending step formation 32 It will be appreciated that while one camming slot 24a and a corresponding follower element 10b would suffice in a fundamental sense, nevertheless, to avoid canting and a tendency of the parts to bind, two (or more) are desired in order to balance the forces acting on the parts during the connecting and disconnecting operations and also with the cap and base members seated together. With two (or more) such camming elements, however, there is a problem of possible ambiguity in determining which of the pin elements will engage Which of the camming slots 24a and it is also necessary, of course, that an letters or numbers of the indicia on the panel 20 occupy an appropriate position in the final seated condition 'of the cap assembly. The formation of the tubular members 32a and 16c resolves the ambiguity by assuring that the parts will go together only with each cam follower pin 1% engaging the correct one of the cam slots 24a. This will be appreciated from an understanding of the connecting procedure as hereinafter described.

In order to connect the cap unit to the base unit B the cap unit is aligned coaxially therewith and is advanced longitudinally against the end of the base unit with the keying surface 16d placed in sliding contact with the keying surface 32e and with the step formations 16 and 32f in substantial circumferential registry. Under this condition keying surface 32d likewise slidably contacts the keying surface 16c and the pins 10b have entered the camming slots 24a to the points of beginning of the inclined portions of those slots. Thereupon, manual rotation of the cap unit in the direction of the arrow R1 (FIGURE 1) relative to the base unit causes the cam follower pins 10b to move along the inclined portions of the slots 24a to a seat at the inner ends of these slots at which the slots are turned substantially at right angles to the longitudinal axis of the units. During this progressive advance of the camming element 10 more deeply into the socket sleeve 24 the base of the lamp L is brought into electrical contact with the socket contact 240 as desired against the resistance of spring 12. The spring 12 is compressed progressively during this movement because the cap body 16 is maintained against longitudinal approach to the base member B by reason of the continued sliding contact of the keying surfaces. However, as the rotational limit is approached the step formation 16 reaches the end of the keying surface 32:: and the step formation 32 reaches the end of the keying surface 16c, permitting the keying surface 16d to advance abruptly into contact with the shoulder 32b and the keying surface 32d to advance into contact with the shoulder surface 16g. Such longitudinal advancement of the cap body 16 into seating relationship with the base (FIGURE 6) is etfectuated by the energy stored in the compressed spring 12 (or other force-producing means). The parts are now locked together because the steps 32 and 16 in the keying surfaces prevent reverse rotation between the cap and base members while such members are seated together.

In order to disconnect the cap or head unit from the base unit for relamping purposes or otherwise, it is first necessary to grasp the cap unit, as by its thumb and finger depressions 22b, and withdraw the same longitudinally from the base unit (without rotation) against the resistance of spring 12 so as to clear the step lformatio'ns 32 and 16 from rotational interference with the longitudinally extending edges of the keying members which they abut. Thereupon, reverse rotation of the head or cap unit in relation to the base unit is permitted, aided by the recoil action of spring 12, in order to retract the cam follower pins b from the cam slots 24a. However, until the cap member is first retracted forcibly against the resistance of spring 12 for a distance equal to the length of the step formations 32] and 161 the units cannot be disengaged and the electric lamp L remains in continuous contact with the terminal 24c as desired.

It will be noted in connection with the foregoing and the accompanying illustrations that insertion and seating of the cap member in the base member does not require pushing inwardly on the cap member with force. Instead, the inward motion of the lamp-retaining camming element sleeve 10 is eifectuated by the cam slots 24a reacting with the follower pins 1012, as the cap and base members are rotated in the correct direction. In fact it is necessary to restrain the cap member body 16 from inward motion during the cam-actuated compression of the spring 12. Such restraint is effectuated by sliding contact between the circumferentially extending keying surfaces.

These and other features and aspects of the invention, together with additional and related advantages thereof, will be evident to those skilled in the art based on an understanding of the present disclosure of its preferred embodiment.

I claim as my invention:

1. A connecting mechanism comprising a first member having a cylindrical bore, a second member having a cylindrical portion engageable in such bore to permit relative longitudinal and rotational movements therebetween, cam and cam follower elements, one on each such member, cooperating to advance the members together by rotating them relatively in one direction, a third member mounted for conjoint rotation and relative longitudinal movement between inner and outer limiting positions on one of the first two members and including means engageable -with the other of said first two members restraining said third member against relative longitudinal movement with respect to said other member during said initial relative advancement of said first and second members, spring means urging the third member towards the outer limiting position, whereby stress in the spring means occurs as the first two members advance together with the third member restrained against such advance, and abutments on the third member and the other of the first two members interengageable, with the first two members advanced together, so as to prevent reverse relative rotation between them, and disengageable by retraction of the third member against resistance of said spring means.

2. The connecting mechanism defined in claim 1, and longitudinally facing abutment surfaces lying in transverse planes on the third member and said other of the first two members, respectively, and interengaged in sliding contact during said relative rotation effecting advancement of the first two members together, such abutments thereby restraining the third member against such advance, said surfaces having such relative angular extents circumferentially as to pass out of such mutual sliding contact as the first two members reach their mutually advanced positions, thereby permitting advance of the third member into position for interengagement of the first-mentioned abutments.

3. The connecting mechanism defined in claim 2, wherein the third member comprises an annular skirt having circumiferentially extending edge portions mutually offset longitudinally and a connecting step portion extending generally longitudinally, said one of the first two members having similar edge and step portions, said step portions comprising the first-mentioned abutments and at least 6 one of said mutually offset edge portions on said members comprising the longitudinally facing abutments.

4. The connecting mechanism defined in claim 3, wherein the third member includes a cap mounted on the skirt, and wherein the spring means comprises a helical spring surrounding a portion of said one of the first two members encircled by said skirt and reacting against stop elements on the skirt and member.

5. The connecting mechanism defined in claim 4, wherein the cap comprises a transluscent window, and said one of the first two members comprises a tubular lamp housing adapted to contain an electric lamp for illuminating the window, and an electric contact mounted in said other of the first two members electrically engageable by the lamp with the first two members advanced together.

6. The connecting mechanism defined in claim 4, wherein said one of the first two members is of tubular form having in its wall a plurality of similar camming slots extending longitudinally and at an incline from one end thereof at which they open, and wherein said other of the first two members carries follower pins slidably engageable in the respective slots.

7. A relampable cap assembly comprising a socket member having a cylindrical end recess therein, a lamp retainer member having a tubular portion adapted to receive an electric lamp therein and to be inserted into the recess for relative longitudinal and rotational movements therebetween, means interacting between the members for advancing them together by rotating them relatively in one direction, a cap member mounted for conjoint rotation and relative longitudinal movement between inner and outer limiting positions on said retainer member, spring means urging the cap member towards the outer limiting position, whereby stress in the spring means occurs as the socket and retainer members advance together with the cap member restrained against such advance, and abutments on the cap and socket members interengageable, with the socket and retainer members advanced together, so as to prevent reverse relative rotation between them, and disengageable by retraction of the cap member against resistance of said spring means.

8. A disengageable electrical connection assembly comprising interconnectable members relatively rotatable about a common axis through an angular range with cooperable keying means in mutual sliding contact to maintain the members apart, said keying means including a step therein at one end of said range permitting the members to seat together by longitudinal approach and thereupon to prevent reverse relative rotation back through said range, cooperable rotation-actuated camming elements carried by the respective members, the camming element on one member being mounted for longitudinal extension and retraction thereon and being progressively extended by the interaction of the camming elements during said relative rotation, and force-producing means also carried by the last-mentioned member yieldably resisting such extension, whereby upon reaching said step the last-mentioned member is drawn to its seat upon the other member by the force exerted by said force-producing means.

9. The assembly defined in claim 8, wherein the forceproducing means includes a spring progressively stressed by said progressive extension.

10. The assembly defined in claim 9, wherein the camming elements comprise interfitting sleeves with an inclined slot in one and a cooperable pin on the other.

11. The assembly defined in claim 10, wherein an electric component having a contact thereon is removably retained in one such sleeve and a cooperable opposing contact is mounted within the other sleeve to be engaged by the first contact as the sleeves come together.

12. The assembly defined in claim 11, wherein one member has a translucent portion and the electric component comprises an electric lamp for illuminating such portion by energization through the cooperable contact.

13. The assembly defined in claim 12, wherein the last-mentioned member comprises an enlarged head having said transluscent portion at one end and having a tubular portion projecting thereifro-m toward its opposite end, the members sleeve being slidably received in and projecting from said tubular portion, opposing stops carried respectively at the inner end of the sleeve exteriorly thereof and near the outer end of the tubular member interiorly thereof, and wherein the spring comprises a helical compression spring interposed between the stops surrounding the sleeve.

14. The assembly defined in claim 11, wherein the member having the component-retaining sleeve comprises an enlarged head at one end and having a tubular portion projecting therefrom toward its opposite end, the members sleeve being slidably received in and projecting from said tubular portion, opposing stops carried respectively at the inner end of the sleeve exteriorly thereof and near the outer end of the tubular member interiorly thereof, and wherein the spring comprises a helical compression spring interposed between the stops surrounding the sleeve.

15. The assembly defined in claim 14, wherein the keying means comprise circumferentially extending edge portions on the tubular portion mutually ofiset from each other longitudinally by a step portion, and a skirt surrounding the sleeve of the other member, having complementally formed edge portions.

16. A disengageable electric component holder and connecting assembly comprising first and second members, one insertable into the other .for relative longitudinal and rotational movements therebetween, said members being adapted to socket an electrical component therewithin and having electric contact means for such a component, camming means on the respective members interengageable upon initiation of insertion of the one member into the other and interacting by relative rotation between the members in one direction to advance the members together longitudinally to a fully inserted position of the insertable member, abutment means on the respective members interengagable with the one member fully inserted in the other to prevent reverse relative rotation between the members, the abutment means of one such member being mounted for relative longitudinal movement thereon out of engagement with the abutment means of the other member, and force-producing means reacting on such movable abutment means resisting such longitudinal movement.

References Cited by the Examiner UNITED STATES PATENTS 1,001,994 8/1911 Schneider 28586 1,093,528 4/1914 Bowes 28586 3,034,088 5/1962 Caller 33990 X NEIL C. READ, Primary Examiner.

D. L. TRAFTON, Assistant Examiner. 

1. A CONNECTING MECHANISM COMPRISING A FIRST MEMBER HAVING A CYLINDRICAL BORE, A SECOND MEMBER HAVING A CYLINDRICAL PORTION ENGAGEABLE IN SUCH BORE TO PERMIT RELATIVE LONGITUDINAL AND ROTATIONAL MOVEMENTS THEREBETWEEN, CAM AND CAM FOLLOWER ELEMENTS, ONE ON EACH SUCH MEMBER, COOPERATING TO ADVANCE THE MEMBERS TOGETHER BY ROTATING THEM RELATIVELY IN ONE DIRECTION, A THIRD MEMBER MOUNTED FOR CONJOINT ROTATION AND RELATIVE LONGITUDINAL MOVEMENT BETWEEN INNER AND OUTER LIMITING POSITIONS ON ONE OF THE FIRST TWO MEMBERS AND INCLUDING MEANS ENGAGEABLE WITH THE OTHER OF SAID FIRST TWO MEMBERS RESTRAINING SAID THIRD MEMBER AGAINST RELATIVE LONGITUDINAL MOVEMENT WITH RESPECT TO SAID OTHER MEMBER DURING SAID INITIAL RELATIVE ADVANCEMENT OF SAID FIRST AND SECOND MEMBERS, SPRING MEANS URGING THE THIRD MEMBER TOWARDS THE OUTER LIMITING POSITION, WHEREBY STRESS IN THE SPRING MEANS OCCURS AS THE FIRST TWO MEMBERS ADVANCE TOGETHER WITH THE THIRD MEMBER RESTRAINED AGAINST SUCH ADVANCE, AND ABUTMENTS ON THE THIRD MEMBER AND THE OTHER OF THE FIRST TWO MEMBERS INTERENGAGEABLE, WITH THE FIRST TWO MEMBERS ADVANCED TOGETHER, SO AS TO PREVENT REVERSE RELATIVE ROTATION BETWEEN THEM, AND DISENGAGEABLE BY RETRACTIOON OF THE THIRD MEMBER AGAINST RESISTANCE OF SAID SPRING MEANS. 